A display panel usually includes a thin film transistor (TFT) substrate. The TFT substrate usually has a substrate and a plurality of TFTs formed on the substrate. Each TFT has a gate electrode, a semiconductor layer, a gate insulator layer disposed between the gate electrode and the semiconductor layer, a drain electrode and a source electrode electrically coupled to opposite sides of the semiconductor layer. However, a resistance is formed between the semiconductor layer and the drain electrode/the source electrode.